Past: Thooku Durai used to be a happy-go-lucky man and a rice mill owner in his village, who uses violent ways to deal with problems.

While chasing a few goons, Thooku Durai stumbles across a doctor named Niranjana, who witnesses his antics and lodges a case against him.

After rushing to the emergency ward, Swetha survives but Niranjana gets infuriated at Thookudurai and tells him to stay away from her and her daughter.

After Gautham Veer threatens Neha that she will find no affection in him if she loses, she resorts to doping, which helps her win the race.

Fearing that her father's reputation and affection would completely vanish, Neha attempts suicide but becomes paralyzed in the process.

After saving her, Thookudurai requests Niranjana to appoint him as Swetha's driver for the next ten days, until her competition, on the condition that he does not reveal him as her father, to which she reluctantly agrees.

[7] D. Imman was signed on to work as the film's music composer, which marked his first collaboration with Ajith Kumar and Siva.

[8] Principal photography was supposed to begin on 23 March 2018[9] but was pushed back significantly to the Tamil Film Producers Council's strike.

The background music was copied for the Bollywood film Marjaavaan, directed by Milap Milan Zaveri and starring Sidharth Malhotra, Tara Sutaria and Riteish Deshmukh in lead roles.

[21] The Times of India rated 3/5, stating, "The film follows the regular template in its narration and changes track at a point keeping in mind to reach all sections of audience.

[22]Behind Woods rated 3/5 stating "Viswasam is packaged with right commercial elements to satisfy the family audience and Thala fans".

[24]India Glitz rated 3/5 stating "Viswasam is Siva – Ajith combo's emotional Pongal treat for families".

[25]Sify rated 3/5 stating "Ajith is endearing and is in tremendous form that the actor looks super energetic as Thooku Durai.

[26]India Today rated 2.5 out of 5 stars stating "After churning out an underwhelming spy thriller Vivegam, Ajith and director Siruthai Siva go back to the rural route with Viswasam.

[27]The News Minute rated 2 out of 5 stars stating "After touring Eastern Europe in 'Vivegam', Siva brings Ajith back to Tamil Nadu and it proves to be a wise move".

[29]Hindustan Times rated 1.5 out of 5 stars stating "While the idea would have been to make audience feel the moment of sweet victory, all it does is ruin the palette for those who enjoy a good commercial film".

[30]Deccan Chronicle stated "Though there’s nothing new by way of story, Siva has made a movie that is all about a mass star – Thala Ajith".

[31]Cinema Express rated 2.5 out of 5 stars stating "Director Siva's biggest achievement is giving us an Ajith who is having fun on screen after a long time, apart from which the film mainly works on surprise value".